Exam 1 (Winter 2014) Flashcards
Phrenology
studying bumps on the skull, could reveal a person’s mental abilities and character traits.
Neurons
nerve cells; basic building block of the nervous system
Dendrites
a neuron’s bushy, branching extensions that receive messages and conduct impulses toward the cell body.
Axon
the neuron extension that passes messages through its branches to other neurons or to muscles or glands.
Myelin sheath
a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop form one node to another.
How are messages sent within a neuron?
Neurons transmit messages when stimulated by signals from our senses or when triggered by chemical signals from neighboring neurons.
Action potential
a neural impulse; a brief electrical charge that travels down an axon.
Synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is the synaptic gap.
Neurotransmitters
chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.
In what ways can drugs affect the behavior of neurotransmitters?
Drugs and other chemicals affect brain chemistry at synapses, often by either exciting or inhibiting neurons’ firing.
Central Nervous System (CNS)
the brain and spinal cord
Peripheral Nervous System (PNS)
the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.
Somatic nervous system
the division of the peripheral nervous system that controls the body’s skeletal muscles (skeletal nervous system)
Autonomic nervous system
the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.
Sympathetic nervous system
the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.
Parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy.
Adrenal glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
Pituitary gland
the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.
what part of the brain controls the master gland?
the hypothalamus
MRI (magnetic resonance imaging)
a technique that uses magnetic fields and radio waves to produce computer generated images of soft tissue. MRI scans show brain anatomy.
fMRI (functional MRI)
a technique for revealing blood flow and brain activity by comparing successive MRI scans. fMRI scans show brain functions.
Glial cells
cells in the nervous system that support, nourish, and protect neurons; they may also play a role in learning and thinking.